1. Field of the Invention
The present invention relates to an image forming apparatus. More specifically, the present invention relates to an image forming apparatus that includes a unit that can be detachably attached to a body of the image forming apparatus.
2. Description of the Related Art
A conventional image forming apparatus of the above type is disclosed in Japanese Patent Application Laid-open No. 2000-235309. The conventional image forming apparatus includes an intermediate-transfer-belt unit that can be detachably attached to a body of the image forming apparatus (hereinafter, “image forming-apparatus body”). A user can attach the intermediate-transfer-belt unit to the image-forming-apparatus body by inserting and pushing it into a space between two side walls of the image forming-apparatus body, or can detach it by pulling it toward the user. During the process of the attachment or detachment, the intermediate-transfer-belt unit is not in contact with a bottom surface of the image-forming-apparatus body. The image forming apparatus further includes guide rails that support the intermediate-transfer-belt unit during a process of the attachment or detachment.
When attaching the intermediate-transfer-belt unit to the image-forming-apparatus body, the user grips a portion on a trailing edge (hereinafter, “trailing edge portion”) of the intermediate-transfer-belt unit in a direction in which the intermediate-transfer-belt unit is inserted into the apparatus body. Then, the user puts, on the guide rails, guide contact members on a leading edge of the intermediate-transfer-belt unit in the insertion direction of the intermediate-transfer-belt unit, and pushes the intermediate-transfer-belt unit into the image-forming-apparatus body along the guide rails. When detaching the intermediate-transfer-belt unit to the image-forming-apparatus body, the user pulls forward the intermediate-transfer-belt unit along the guide rails, and lifts up the intermediate-transfer-belt unit before the guide contact members come off the guide rails.
Because the guide rails support the intermediate-transfer-belt unit during the detachment or attachment, the intermediate-transfer-belt unit can be detached from or attached to the image-forming-apparatus body without making a physical contact with the bottom surface of the image forming apparatus.
However, sometimes the user may relax the grip on the front edge portion of the intermediate-transfer-belt unit even though the guide contact members are not yet put on the guide rails. In such a case, the intermediate-transfer-belt unit pivots on the trailing edge portion that the user grips such that the leading portion of the intermediate-transfer-belt unit falls. The leading portion may bump against and damage, for example, the bottom surface of the image-forming-apparatus body, or the intermediate-transfer-belt unit itself may get damaged.
Similarly, during detachment of the intermediate-transfer-belt unit, the intermediate-transfer-belt unit may pivot on the trailing edge portion that the user grips and the leading edge of the intermediate-transfer-belt unit may fall, in case the guide contact members come off the guide rails before the user lifts up the intermediate-transfer-belt unit. Even in this case, the leading edge of the intermediate-transfer-belt unit can bump and damage, for example, the bottom surface of the image-forming-apparatus body, or the intermediate-transfer-belt unit itself can get damaged.
Although the intermediate-transfer-belt unit is explained above as a unit that can be detachably attached to the image-forming-apparatus body, any unit can have the above drawbacks as long as the unit can be detached from or attached to the image-forming-apparatus body while being supported by guide rails and being not in contact with the bottom surface of the image-forming-apparatus body.